/*
 * Copyright (C) 2007 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.example.android.apis.graphics;

import com.example.android.apis.R;

import android.content.Context;
import android.graphics.*;
import android.os.Bundle;
import android.view.*;

import java.io.InputStream;

public class AlphaBitmap extends GraphicsActivity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(new SampleView(this));
	}

	private static class SampleView extends View {
		private Bitmap mBitmap;
		private Bitmap mBitmap2;
		private Bitmap mBitmap3;
		private Shader mShader;

		private static void drawIntoBitmap(Bitmap bm) {
			float x = bm.getWidth();
			float y = bm.getHeight();
			Canvas c = new Canvas(bm);
			Paint p = new Paint();
			p.setAntiAlias(true);

			p.setAlpha(0x80);
			c.drawCircle(x / 2, y / 2, x / 2, p);

			p.setAlpha(0x30);
			p.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC));
			p.setTextSize(60);
			p.setTextAlign(Paint.Align.CENTER);
			Paint.FontMetrics fm = p.getFontMetrics();
			c.drawText("Alpha", x / 2, (y - fm.ascent) / 2, p);
		}

		public SampleView(Context context) {
			super(context);
			setFocusable(true);

			InputStream is = context.getResources().openRawResource(
					R.drawable.app_sample_code);
			mBitmap = BitmapFactory.decodeStream(is);
			mBitmap2 = mBitmap.extractAlpha();
			mBitmap3 = Bitmap.createBitmap(200, 200, Bitmap.Config.ALPHA_8);
			drawIntoBitmap(mBitmap3);

			mShader = new LinearGradient(0, 0, 100, 70, new int[] { Color.RED,
					Color.GREEN, Color.BLUE }, null, Shader.TileMode.MIRROR);
		}

		@Override
		protected void onDraw(Canvas canvas) {
			canvas.drawColor(Color.WHITE);

			Paint p = new Paint();
			float y = 10;

			p.setColor(Color.RED);
			canvas.drawBitmap(mBitmap, 10, y, p);
			y += mBitmap.getHeight() + 10;
			canvas.drawBitmap(mBitmap2, 10, y, p);
			y += mBitmap2.getHeight() + 10;
			p.setShader(mShader);
			canvas.drawBitmap(mBitmap3, 10, y, p);
		}
	}
}
